Optimized functionality through interoperation of doppler and image based vessel differentiation

PRIORITY

0001This application claims the benefit of priority to U.S. Provisional Application No. 63/275,242, filed Nov. 3, 2021, which is incorporated by reference in its entirety into this application.

BACKGROUND

0002Ultrasound imaging is a widely accepted tool for guiding interventional instruments such as needles to targets such as blood vessels or organs in the human body. In order to successfully guide, for example, a needle to a blood vessel using ultrasound imaging, the needle is monitored in real-time both immediately before and after a percutaneous puncture in order to enable a clinician to determine the distance and the orientation of the needle to the blood vessel and ensure successful access thereto. Although, it may be difficult to identify the blood vessel as a vein or artery as portrayed in an ultrasound image.

0003Doppler ultrasound is a noninvasive approach to estimating the blood flow through your blood vessels by bouncing high-frequency sound waves (ultrasound) off circulating red blood cells. A doppler ultrasound can estimate how fast blood flows by measuring the rate of change in its pitch (frequency). Doppler ultrasound may also detect a direction of blood flow. For example, doppler ultrasound can differentiate an artery from a vein since the direction of blood flow within an artery is generally in the opposite direction from a blood flow within an adjacent vein.

0004Disclosed herein are systems and methods for enhancing the identification of blood vessels within ultrasound images via doppler ultrasound.

SUMMARY

0005Disclosed herein is an ultrasound-imaging system including, in some embodiments, an ultrasound probe coupled with a console. The ultrasound probe includes an array of ultrasonic transducers, where activated ultrasonic transducers of the array of ultrasonic transducers are configured to emit generated ultrasound signals into a patient, receive reflected ultrasound signals from the patient, and convert the reflected ultrasound signals into corresponding electrical signals of the ultrasound signals for processing into ultrasound image data and doppler ultrasound data.

0006The console includes one or more processors and a non-transitory computer-readable medium having stored thereon logic that, when executed by the one or more processors, causes operations including: (i) obtaining an ultrasound image of a predefined target area of the patient, (ii) detecting one or more blood vessels within the ultrasound image, (iii) obtaining doppler ultrasound data pertaining to blood flow within the one or more blood vessels, (iv) determining a condition of the blood flow based at least partially on doppler ultrasound data, and (v) identifying the one or more blood vessels as a vein or alternatively as an artery based at least partially on the condition of the blood flow within the one or more blood vessels.

0007In some embodiments, the operations further include determining a direction of the blood flow within the one or more blood vessels based on doppler ultrasound data, where the direction is determined with respect to an image plane of the ultrasound image, and the operations further include identifying the one or more blood vessels as a vein or an artery based at least partially on the direction of the blood flow.

0008In some embodiments, the operations further include determining a magnitude of the blood flow within the one or more blood vessels based on doppler ultrasound data and further identifying the one or more blood vessels as a vein or an artery based at least partially on the magnitude of the blood flow.

0009In some embodiments, the operations further include determining a pulsatility of the blood flow within the one or more blood vessels based on doppler ultrasound data, comparing the pulsatility with a pulsatility limit stored in memory, and as a result of the comparison, further at least partially identifying the one or more blood vessels (i) as an artery when the pulsatility exceeds the pulsatility limit or (ii) as a vein when the pulsatility is less than the pulsatility limit.

0010In some embodiments, the system is configured to obtain an ECG signal, and the operations further include determining the pulsatility of the blood flow in coordination with the ECG signal.

0011In some embodiments, determining the condition includes determining a pulse timing difference between a blood flow pulse within a first blood vessel and a corresponding blood flow pulse within an second blood vessel based on doppler ultrasound data and the operations further include identifying at least one of the first blood vessel or the second blood vessel as a vein or as an artery based at least partially on the pulse timing difference.

0012In some embodiments, the operations further include determining a cross-sectional shape of the one or more blood vessels and further identifying the one or more blood vessels as a vein or an artery based at least partially on the cross-sectional shape. In further embodiments, identifying the one or more blood vessels based on the cross-sectional shape includes comparing the shape of the one or more blood vessels with an elliptical shape limit stored in memory and further as a result of the comparison, identifying the one or more blood vessels (i) as an artery when the cross-sectional shape is less than the elliptical shape limit or (ii) as a vein when the cross-sectional shape exceeds the elliptical shape limit.

0013In some embodiments, the operations further include determining a confidence for the identity of the one or more blood vessels based on one or more of the direction of the blood flow, the magnitude of the blood flow, the pulsatility of the blood flow, the pulse timing difference of the blood flow, or the cross-sectional shape.

0014In some embodiments, the operations further include defining a doppler ultrasound window extending at least partially across the ultrasound image, where the doppler ultrasound window defines a portion of the ultrasound image for obtaining doppler ultrasound data and the doppler ultrasound window encompasses the one or more blood vessels. Defining the doppler ultrasound window may include automatically defining the doppler ultrasound window upon detecting the one or more blood vessels. Defining the doppler ultrasound window may also include receiving an input via an input device of the system and defining the doppler ultrasound window based on the input, where the input includes a selected portion of the ultrasound image. The input device may include a graphical user interface of the display and/or control buttons of the ultrasound probe.

0015In some embodiments, the ultrasound probe further includes an array of magnetic sensors configured to convert magnetic signals from a magnetized medical device into corresponding electrical signals of the magnetic signals for processing by the processor into position and/or orientation information of the magnetized medical device with respect to the predefined target area. In further embodiments, the operations further include superimposing an iconographic representation of the medical device atop the ultrasound image and the operations may further include defining the doppler ultrasound window based on the position and/or orientation of the iconographic representation of the medical device atop the ultrasound image. In some embodiments, the operations further include selecting a blood vessel of interest from the one or more blood vessels based on the position and/or orientation of the iconographic representation of the medical device atop the ultrasound image.

0016In some embodiments, the ultrasound probe further includes an accelerometer, a gyroscope, a magnetometer, or a combination thereof configured to provide tracking data to the console, where the tracking data pertains to the position and/or orientation of the ultrasound probe with respect to a trajectory of the one or more blood vessels. In such embodiments, the operations may further include processing the tracking data in combination with obtaining the doppler ultrasound data to enhance an accuracy of the determining of the direction and/or magnitude of blood flow within the one or more blood vessels.

0017In some embodiments, the operations further include portraying the ultrasound image on a display of the system and superimposing a notification atop the ultrasound image, where the notification includes the identity of the blood vessel. In some embodiments, the notification further includes the confidence for the identity of the blood vessel.

0018Also disclosed herein is a method of an ultrasound-imaging system including a non-transitory computer-readable medium (“CRM”) having executable logic that causes the ultrasound-imaging system to perform a set of operations for ultrasound imaging when the logic is executed by a processor of a console of the ultrasound-imaging system. The method includes activating ultrasonic transducers of an array of ultrasonic transducers of an ultrasound probe communicatively coupled to the console, where the ultrasonic transducers emit generated ultrasound signals into a patient, receive reflected ultrasound signals from the patient, and convert the reflected ultrasound signals into corresponding electrical signals of the ultrasound signals for processing into ultrasound image data and doppler ultrasound data. The method further includes (i) obtaining an ultrasound image of a predefined target area of the patient, (ii) detecting one or more blood vessels within the ultrasound image, (iii) obtaining doppler ultrasound data pertaining to blood flow within the one or more blood vessels, (iv) determining a condition of the blood flow based at least partially on doppler ultrasound data, and (v) identifying the one or more blood vessels as a vein or alternatively as an artery based at least partially on the condition of the blood flow within the one or more blood vessels.

0019In some embodiments, the method further includes determining a direction of the blood flow within the one or more blood vessels based on doppler ultrasound data, where the direction is determined with respect to an image plane of the ultrasound image, and the method further includes identifying the one or more blood vessels as a vein or an artery based at least partially on the direction of the blood flow.

0020In some embodiments, the method further includes determining a magnitude of the blood flow within the one or more blood vessels based on doppler ultrasound data and further identifying the one or more blood vessels as a vein or an artery based at least partially on the magnitude of the blood flow.

0021In some embodiments, the method further includes determining a pulsatility of the blood flow within the one or more blood vessels based on doppler ultrasound data, comparing the pulsatility with a pulsatility limit stored in memory, and as a result of the comparison, further at least partially identifying the one or more blood vessels (i) as an artery when the pulsatility exceeds the pulsatility limit or (ii) as a vein when the pulsatility is less than the pulsatility limit. In some embodiments of the method, the system is configured to obtain an ECG signal, and the method further includes determining the pulsatility of the blood flow in coordination with the ECG signal.

0022In some embodiments, determining the condition includes determining a pulse timing difference between a blood flow pulse within a first blood vessel and a corresponding blood flow pulse within an second blood vessel based on doppler ultrasound data and the method further includes identifying at least one of the first blood vessel or the second blood vessel as a vein or as an artery based at least partially on the pulse timing difference.

0023In some embodiments, the method further includes determining a cross-sectional shape of the one or more blood vessels and further identifying the one or more blood vessels as a vein or an artery based at least partially on the cross-sectional shape.

0024In some embodiments, the method further includes determining a confidence for the identity of the one or more blood vessels based on one or more of the direction of the blood flow, the magnitude of the blood flow, the pulsatility of the blood flow, the pulse timing difference of the blood flow, or the cross-sectional shape.

0025In some embodiments, the method further includes defining a doppler ultrasound window extending at least partially across the ultrasound image, where the doppler ultrasound window defines a portion of the ultrasound image for obtaining doppler ultrasound data and the doppler ultrasound window encompasses the one or more blood vessels.

0026In some embodiments of the method, defining the doppler ultrasound window includes automatically defining the doppler ultrasound window upon detecting the one or more blood vessels. In some embodiments of the method defining the doppler ultrasound window includes receiving an input via an input device of the system and defining the doppler ultrasound window based on the input, where the input includes a selected portion of the ultrasound image and where the input device includes one or more of a graphical user interface of the display or control buttons of the ultrasound probe.

0027In some embodiments, the method further includes portraying the ultrasound image on a display of the system and superimposing a notification atop the ultrasound image, where the notification includes the identity of the blood vessel and/or the confidence for the identity of the blood vessel.

0028In some embodiments of the method, the ultrasound probe further includes an array of magnetic sensors configured to convert magnetic signals from a magnetized medical device into corresponding electrical signals of the magnetic signals for processing by the processor into position and/or orientation information of the magnetized medical device with respect to the predefined target area. In such embodiments, the method further includes superimposing an iconographic representation of the medical device atop the ultrasound image and defining the doppler ultrasound window based on the position and/or orientation of the iconographic representation of the medical device atop the ultrasound image.

0029These and other features of the concepts provided herein will become more apparent to those of skill in the art in view of the accompanying drawings and following description, which describe particular embodiments of such concepts in greater detail.

DRAWINGS

0030<figref idref="DRAWINGS">FIG. <b>1</b></figref> illustrates an ultrasound-imaging system and a patient in accordance with some embodiments.

0031<figref idref="DRAWINGS">FIG. <b>2</b></figref> illustrates a block diagram of a console of the ultrasound-imaging system of <figref idref="DRAWINGS">FIG. <b>1</b></figref> in accordance with some embodiments.

0032<figref idref="DRAWINGS">FIG. <b>3</b>A</figref> illustrates an ultrasound probe of the ultrasound-imaging system imaging a blood vessel in accordance with some embodiments.

0033<figref idref="DRAWINGS">FIG. <b>3</b>B</figref> illustrates an ultrasound image of the blood vessel of <figref idref="DRAWINGS">FIG. <b>3</b>A</figref> on a display screen of the ultrasound-imaging system in accordance with some embodiments.

0034<figref idref="DRAWINGS">FIG. <b>4</b></figref> illustrates the ultrasound probe of the ultrasound-imaging system configured as a 2-D ultrasound probe in accordance with some embodiments.

0035<figref idref="DRAWINGS">FIG. <b>5</b>A</figref> illustrate an exemplary subcutaneous target area of a patient including a blood vessel for ultrasound imaging in accordance with some embodiments.

0036<figref idref="DRAWINGS">FIG. <b>5</b>B</figref> illustrate the exemplary subcutaneous target area of <figref idref="DRAWINGS">FIG. <b>5</b>A</figref> further illustrating the application of doppler ultrasound in accordance with some embodiments.

0037<figref idref="DRAWINGS">FIG. <b>6</b>A</figref> illustrate another exemplary subcutaneous target area of a patient for ultrasound imaging including a blood vessel and an additional anatomical element in accordance with some embodiments.

0038<figref idref="DRAWINGS">FIG. <b>6</b>B</figref> illustrate the subcutaneous target area of <figref idref="DRAWINGS">FIG. <b>6</b>A</figref> further illustrating the application of doppler ultrasound in accordance with some embodiments.

0039<figref idref="DRAWINGS">FIG. <b>7</b></figref> illustrates a display of the system of <figref idref="DRAWINGS">FIG. <b>1</b></figref> portraying an ultrasound image of a blood vessel in accordance with some embodiments.

0040<figref idref="DRAWINGS">FIG. <b>8</b></figref> illustrates a method of system operations that may executed according to system logic in accordance with some embodiments.

DESCRIPTION

0041Before some particular embodiments are disclosed in greater detail, it should be understood that the particular embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that a particular embodiment disclosed herein can have features that can be readily separated from the particular embodiment and optionally combined with or substituted for features of any of a number of other embodiments disclosed herein.

0042Regarding terms used herein, it should also be understood the terms are for the purpose of describing some particular embodiments, and the terms do not limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps in a group of features or steps, and do not supply a serial or numerical limitation. For example, “first,” “second,” and “third” features or steps need not necessarily appear in that order, and the particular embodiments including such features or steps need not necessarily be limited to the three features or steps. Labels such as “left,” “right,” “top,” “bottom,” “front,” “back,” and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions. Singular forms of “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

0043With respect to “proximal,” a “proximal portion” or a “proximal-end portion” of, for example, a catheter disclosed herein includes a portion of the catheter intended to be near a clinician when the catheter is used on a patient. Likewise, a “proximal length” of, for example, the catheter includes a length of the catheter intended to be near the clinician when the catheter is used on the patient. A “proximal end” of, for example, the catheter includes an end of the catheter intended to be near the clinician when the catheter is used on the patient. The proximal portion, the proximal-end portion, or the proximal length of the catheter can include the proximal end of the catheter; however, the proximal portion, the proximal-end portion, or the proximal length of the catheter need not include the proximal end of the catheter. That is, unless context suggests otherwise, the proximal portion, the proximal-end portion, or the proximal length of the catheter is not a terminal portion or terminal length of the catheter.

0044With respect to “distal,” a “distal portion” or a “distal-end portion” of, for example, a catheter disclosed herein includes a portion of the catheter intended to be near or in a patient when the catheter is used on the patient. Likewise, a “distal length” of, for example, the catheter includes a length of the catheter intended to be near or in the patient when the catheter is used on the patient. A “distal end” of, for example, the catheter includes an end of the catheter intended to be near or in the patient when the catheter is used on the patient. The distal portion, the distal-end portion, or the distal length of the catheter can include the distal end of the catheter; however, the distal portion, the distal-end portion, or the distal length of the catheter need not include the distal end of the catheter. That is, unless context suggests otherwise, the distal portion, the distal-end portion, or the distal length of the catheter is not a terminal portion or terminal length of the catheter.

0045Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art.

0000Ultrasound-Imaging Systems

0046<figref idref="DRAWINGS">FIG. <b>1</b></figref> illustrates an ultrasound-imaging system <b>100</b>, a needle <b>112</b>, and a patient P in accordance with some embodiments. <figref idref="DRAWINGS">FIG. <b>2</b></figref> illustrates a block diagram of the ultrasound-imaging system <b>100</b> in accordance with some embodiments. <figref idref="DRAWINGS">FIG. <b>3</b>A</figref> illustrates an ultrasound probe <b>106</b> of the ultrasound-imaging system <b>100</b> imaging a blood vessel of the patient P prior to accessing the blood vessel in accordance with some embodiments. <figref idref="DRAWINGS">FIG. <b>3</b>B</figref> illustrates an ultrasound image of the blood vessel of <figref idref="DRAWINGS">FIG. <b>3</b>A</figref> on a display screen <b>104</b> of the ultrasound-imaging system <b>100</b> with an iconographic representation of the needle <b>112</b> in accordance with some embodiments.

0047As shown, the ultrasound-imaging system <b>100</b> includes a console <b>102</b>, the display screen <b>104</b>, and the ultrasound probe <b>106</b>. The ultrasound-imaging system <b>100</b> is useful for imaging a target such as a blood vessel or an organ within a body of the patient P prior to a percutaneous puncture with the needle <b>112</b> for inserting the needle <b>112</b> or another medical device into the target and accessing the target. Indeed, the ultrasound-imaging system <b>100</b> is shown in <figref idref="DRAWINGS">FIG. <b>1</b></figref> in a general relationship to the patient P during an ultrasound-based medical procedure to place a catheter <b>108</b> into the vasculature of the patient P through a skin insertion site S created by a percutaneous puncture with the needle <b>112</b>. It should be appreciated that the ultrasound-imaging system <b>100</b> can be useful in a variety of ultrasound-based medical procedures other than catheterization. For example, the percutaneous puncture with the needle <b>112</b> can be performed to biopsy tissue of an organ of the patient P.

0048The console <b>102</b> houses a variety of components of the ultrasound-imaging system <b>100</b>, and it is appreciated the console <b>102</b> can take any of a variety of forms. A processor <b>116</b> and memory <b>118</b> such as random-access memory (“RAM”) or non-volatile memory (e.g., electrically erasable programmable read-only memory [“EEPROM”]) is included in the console <b>102</b> for controlling functions of the ultrasound-imaging system <b>100</b>, as well as executing various logic operations or algorithms during operation of the ultrasound-imaging system <b>100</b> in accordance with executable logic <b>120</b> therefor stored in the memory <b>118</b> for execution by the processor <b>116</b>. For example, the console <b>102</b> is configured to instantiate by way of the logic <b>120</b> one or more processes for adjusting a distance of activated ultrasonic transducers <b>149</b> from a predefined target area (e.g., an area including a blood vessel), an orientation of the activated ultrasonic transducers <b>149</b> to the predefined target area, or both the distance and the orientation of the activated ultrasonic transducers <b>149</b> with respect to the predefined target area, as well as process electrical signals from the ultrasound probe <b>106</b> into ultrasound images. Adjusting the activated ultrasonic transducers <b>149</b> uses ultrasound-imaging data, magnetic-field data, shape-sensing data, or a combination thereof received by the console <b>102</b> for activating certain ultrasonic transducers of a 2-D array of the ultrasonic transducers <b>148</b> or moving those already activated in a linear array of the ultrasonic transducers <b>148</b>. A digital controller/analog interface <b>122</b> is also included with the console <b>102</b> and is in communication with both the processor <b>116</b> and other system components to govern interfacing between the ultrasound probe <b>106</b> and other system components set forth herein.

0049The ultrasound-imaging system <b>100</b> further includes ports <b>124</b> for connection with additional components such as optional components <b>126</b> including a printer, storage media, keyboard, etc. The ports <b>124</b> can be universal serial bus (“USB”) ports, though other types of ports can be used for this connection or any other connections shown or described herein. A power connection <b>128</b> is included with the console <b>102</b> to enable operable connection to an external power supply <b>130</b>. An internal power supply <b>132</b> (e.g., a battery) can also be employed either with or exclusive of the external power supply <b>130</b>. Power management circuitry <b>134</b> is included with the digital controller/analog interface <b>122</b> of the console <b>102</b> to regulate power use and distribution.

0050Optionally, a stand-alone optical interrogator <b>154</b> can be communicatively coupled to the console <b>102</b> by way of one of the ports <b>124</b>. Alternatively, the console <b>102</b> can include an integrated optical interrogator integrated into the console <b>102</b>. Such an optical interrogator is configured to emit input optical signals into a companion optical-fiber stylet <b>156</b> for shape sensing with the ultrasound-imaging system <b>100</b>, which optical-fiber stylet <b>156</b>, in turn, is configured to be inserted into a lumen of a medical device such as the needle <b>112</b>, and convey the input optical signals from the optical interrogator <b>154</b> to a number of FBG sensors along a length of the optical-fiber stylet <b>156</b>. The optical interrogator <b>154</b> is also configured to receive reflected optical signals conveyed by the optical-fiber stylet <b>156</b> reflected from the number of FBG sensors, the reflected optical signals indicative of a shape of the optical-fiber stylet <b>156</b>. The optical interrogator <b>154</b> is also configured to convert the reflected optical signals into corresponding electrical signals for processing by the console <b>102</b> into distance and orientation information with respect to the target for adjusting a distance of the activated ultrasonic transducers <b>149</b>, an orientation of the activated ultrasonic transducers <b>149</b>, or both the distance and the orientation of the activated ultrasonic transducers <b>149</b> with respect to the target or the medical device when it is brought into proximity of the target. For example, the distance and orientation of the activated ultrasonic transducers <b>149</b> can be adjusted with respect to a blood vessel as the target. Indeed, an image plane can be established by the activated ultrasonic transducers <b>149</b> being perpendicular or parallel to the blood vessel in accordance with an orientation of the blood vessel. The distance and orientation information can also be used for displaying an iconographic representation of the medical device on the display.

0051The system <b>100</b> may optionally include an ECG monitor <b>170</b> communicatively coupled with the console <b>102</b> by way of one of the ports <b>124</b>. Alternatively, the console <b>102</b> can include an ECG monitor integrated into the console <b>102</b>. The ECG monitor <b>170</b> includes one or more electrodes (not shown) coupleable with the patient P for obtaining ECG signals. The ECG monitor <b>170</b> is configured to receive the ECG signals from the electrodes coupled with the patient P and convert the ECG signals into electrical signals for processing by the console <b>102</b>.

0052The display screen <b>104</b> is integrated into the console <b>102</b> to provide a GUI and display information for a clinician during such as one-or-more ultrasound images of the target area of the patient P attained by the ultrasound probe <b>106</b>. In addition, the ultrasound-imaging system <b>100</b> enables the distance and orientation of a magnetized medical device such as the needle <b>112</b> to be superimposed in real-time atop an ultrasound image of the target, thus enabling a clinician to accurately guide the magnetized medical device to an intended target. Notwithstanding the foregoing, the display screen <b>104</b> can alternatively be separate from the console <b>102</b> and communicatively coupled thereto. A console button interface <b>136</b> and control buttons <b>110</b> (see <figref idref="DRAWINGS">FIG. <b>1</b></figref>) included on the ultrasound probe <b>106</b> can be used to immediately call up a desired mode to the display screen <b>104</b> by the clinician for assistance in an ultrasound-based medical procedure. In some embodiments, the display screen <b>104</b> is an LCD device.

0053The ultrasound probe <b>106</b> is employed in connection with ultrasound-based visualization of a target such as a blood vessel (see <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>) in preparation for inserting the needle <b>112</b> or another medical device into the target. Such visualization gives real-time ultrasound guidance and assists in reducing complications typically associated with such insertion, including inadvertent arterial puncture, hematoma, pneumothorax, etc. As described in more detail below, the ultrasound probe <b>106</b> is configured to provide to the console <b>102</b> electrical signals corresponding to both the ultrasound-imaging data, the magnetic-field data, the shape-sensing data, or a combination thereof for the real-time ultrasound guidance.

0054<figref idref="DRAWINGS">FIG. <b>4</b></figref> illustrates the ultrasound probe <b>106</b> of the ultrasound-imaging system <b>100</b> configured as a 2-D ultrasound probe <b>106</b> in accordance with some embodiments. The ultrasound probe <b>106</b> includes a probe head <b>114</b> that houses a mounted and moveable (e.g., translatable or rotatable along a central axis) linear array of the ultrasonic transducers <b>148</b> or a 2-D array of the ultrasonic transducers <b>148</b>, wherein the ultrasonic transducers <b>148</b> are piezoelectric transducers or capacitive micro-machined ultrasonic transducers (“CMUTs”). When the ultrasound probe <b>106</b> is configured with the 2-D array of the ultrasonic transducers <b>148</b>, a subset of the ultrasonic transducers <b>148</b> is linearly activated as needed for ultrasound imaging in accordance with ultrasound-imaging data, magnetic-field data, shape-sensing data, or a combination thereof to maintain the target in an image plane or switch to a different image plane (e.g., from perpendicular to a medical-device plane to parallel to the medical-device plane) including the target.

0055The probe head <b>114</b> is configured for placement against skin of the patient P proximate a prospective needle-insertion site where the activated ultrasonic transducers <b>149</b> in the probe head <b>114</b> can generate and emit the generated ultrasound signals into the patient P in a number of pulses, receive reflected ultrasound signals or ultrasound echoes from the patient P by way of reflection of the generated ultrasonic pulses by the body of the patient P, and convert the reflected ultrasound signals into corresponding electrical signals for processing into ultrasound images by the console <b>102</b> to which the ultrasound probe <b>106</b> is communicatively coupled. In this way, a clinician can employ the ultrasound-imaging system <b>100</b> to determine a suitable insertion site and establish vascular access with the needle <b>112</b> or another medical device.

0056The ultrasound probe <b>106</b> further includes the control buttons <b>110</b> for controlling certain aspects of the ultrasound-imaging system <b>100</b> during an ultrasound-based medical procedure, thus eliminating the need for the clinician to reach out of a sterile field around the patient P to control the ultrasound-imaging system <b>100</b>. For example, a control button of the control buttons <b>110</b> can be configured to select or lock onto the target (e.g., a blood vessel, an organ, etc.) when pressed for visualization of the target in preparation for inserting the needle <b>112</b> or another medical device into the target. Such a control button can also be configured to deselect the target, which is useful whether the target was selected by the control button or another means such as by holding the ultrasound probe <b>106</b> stationary over the target to select the target, issuing a voice command to select the target, or the like.

0057<figref idref="DRAWINGS">FIG. <b>2</b></figref> shows that the ultrasound probe <b>106</b> further includes a button and memory controller <b>138</b> for governing button and ultrasound probe <b>106</b> operation. The button and memory controller <b>138</b> can include non-volatile memory (e.g., EEPROM). The button and memory controller <b>138</b> is in operable communication with a probe interface <b>140</b> of the console <b>102</b>, which includes an input/output (“I/O”) component <b>142</b> for interfacing with the ultrasonic transducers <b>148</b> and a button and memory I/O component <b>144</b> for interfacing with the button and memory controller <b>138</b>.

0058Also as seen in <figref idref="DRAWINGS">FIGS. <b>2</b> and <b>3</b>A</figref>, the ultrasound probe <b>106</b> can include a magnetic-sensor array <b>146</b> for detecting a magnetized medical device such as the needle <b>112</b> during ultrasound-based medical procedures. The magnetic-sensor array <b>146</b> includes a number of magnetic sensors <b>150</b> embedded within or included on a housing of the ultrasound probe <b>106</b>. The magnetic sensors <b>150</b> are configured to detect a magnetic field or a disturbance in a magnetic field as magnetic signals associated with the magnetized medical device when it is in proximity to the magnetic-sensor array <b>146</b>. The magnetic sensors <b>150</b> are also configured to convert the magnetic signals from the magnetized medical device (e.g., the needle <b>112</b>) into electrical signals for the console <b>102</b> to process into distance and orientation information for the magnetized medical device with respect to the predefined target, as well as for display of an iconographic representation of the magnetized medical device on the display screen <b>104</b>. (See the magnetic field B of the needle <b>112</b> in <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>.) Thus, the magnetic-sensor array <b>146</b> enables the ultrasound-imaging system <b>100</b> to track the needle <b>112</b> or the like.

0059Though configured here as magnetic sensors, it is appreciated that the magnetic sensors <b>150</b> can be sensors of other types and configurations. Also, though they are described herein as included with the ultrasound probe <b>106</b>, the magnetic sensors <b>150</b> of the magnetic-sensor array <b>146</b> can be included in a component separate from the ultrasound probe <b>106</b> such as a sleeve into which the ultrasound probe <b>106</b> is inserted or even a separate handheld device. The magnetic sensors <b>150</b> can be disposed in an annular configuration about the probe head <b>114</b> of the ultrasound probe <b>106</b>, though it is appreciated that the magnetic sensors <b>150</b> can be arranged in other configurations, such as in an arched, planar, or semi-circular arrangement.

0060Each magnetic sensor of the magnetic sensors <b>150</b> includes three orthogonal sensor coils for enabling detection of a magnetic field in three spatial dimensions. Such 3-dimensional (“3-D”) magnetic sensors can be purchased, for example, from Honeywell Sensing and Control of Morristown, NJ. Further, the magnetic sensors <b>150</b> are configured as Hall-effect sensors, though other types of magnetic sensors could be employed. Further, instead of 3-D sensors, a plurality of 1-dimensional (“1-D”) magnetic sensors can be included and arranged as desired to achieve 1-, 2-, or 3-D detection capability.

0061Five magnetic sensors <b>150</b> are included in the magnetic-sensor array <b>146</b> so as to enable detection of a magnetized medical device such as the needle <b>112</b> in three spatial dimensions (e.g., X, Y, Z coordinate space), as well as the pitch and yaw orientation of the magnetized medical device itself. Detection of the magnetized medical device in accordance with the foregoing when the magnetized medical device is brought into proximity of the ultrasound probe <b>106</b> allows for dynamically adjusting a distance of the activated ultrasonic transducers <b>149</b>, an orientation of the activated ultrasonic transducers <b>149</b>, or both the distance and the orientation of the activated ultrasonic transducers <b>149</b> with respect to the target or the magnetized medical device. For example, the distance and orientation of the activated ultrasonic transducers <b>149</b> can be adjusted with respect to a blood vessel as the target. Indeed, an image plane can be established by the activated ultrasonic transducers <b>149</b> being perpendicular or parallel to the blood vessel in accordance with an orientation of the blood vessel. Note that in some embodiments, orthogonal sensing components of two or more of the magnetic sensors <b>150</b> enable the pitch and yaw attitude of the magnetized medical device to be determined, which enables tracking with relatively high accuracy. In other embodiments, fewer than five or more than five magnetic sensors of the magnetic sensors <b>150</b> can be employed in the magnetic-sensor array <b>146</b>. More generally, it is appreciated that the number, size, type, and placement of the magnetic sensors <b>150</b> of the magnetic-sensor array <b>146</b> can vary from what is explicitly shown here.

0062As shown in <figref idref="DRAWINGS">FIG. <b>2</b></figref>, the ultrasound probe <b>106</b> can further include an inertial measurement unit (“IMU”) <b>158</b> or any one or more components thereof for inertial measurement selected from an accelerometer <b>160</b>, a gyroscope <b>162</b>, and a magnetometer <b>164</b> configured to provide positional-tracking data of the ultrasound probe <b>106</b> to the console <b>102</b> for tracking the position and/or orientation of the image plane.

0063The processor <b>116</b> is further configured to execute the logic <b>120</b> for processing the positional-tracking data for assessing a distance of the activated ultrasonic transducers <b>149</b> from the blood vessel, the orientation of the activated ultrasonic transducers <b>149</b> with respect to the blood vessel, or both the distance and the orientation of the activated ultrasonic transducers <b>149</b> with respect to the blood vessel to define an orientation of the image plane with respect the blood vessel.

0064It is appreciated that a medical device of a magnetizable material enables the medical device (e.g., the needle <b>112</b>) to be magnetized by a magnetizer, if not already magnetized, and tracked by the ultrasound-imaging system <b>100</b> when the magnetized medical device is brought into proximity of the magnetic sensors <b>150</b> of the magnetic-sensor array <b>146</b> or inserted into the body of the patient P during an ultrasound-based medical procedure. Such magnetic-based tracking of the magnetized medical device assists the clinician in placing a distal tip thereof in a desired location, such as in a lumen of a blood vessel, by superimposing a simulated needle image representing the real-time distance and orientation of the needle <b>112</b> over an ultrasound image of the body of the patient P being accessed by the magnetized medical device. Such a medical device can be stainless steel such as SS 304 stainless steel; however, other suitable needle materials that are capable of being magnetized can be employed. So configured, the needle <b>112</b> or the like can produce a magnetic field or create a magnetic disturbance in a magnetic field detectable as magnetic signals by the magnetic-sensor array <b>146</b> of the ultrasound probe <b>106</b> so as to enable the distance and orientation of the magnetized medical device to be tracked by the ultrasound-imaging system <b>100</b> for adjusting the distance of the activated ultrasonic transducers <b>149</b>, an orientation of the activated ultrasonic transducers <b>149</b>, or both the distance and the orientation of the activated ultrasonic transducers <b>149</b> with respect to the magnetized medical device.

0065During operation of the ultrasound-imaging system <b>100</b>, the probe head <b>114</b> of the ultrasound probe <b>106</b> is placed against skin of the patient P. An ultrasound beam <b>352</b> is produced so as to ultrasonically image a portion of a target area that may include a blood vessel beneath a surface of the skin of the patient P such as the blood vessel <b>351</b> of <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>. (See <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>.). The ultrasound beam defines an image plane <b>353</b> having a front side <b>353</b>A consistent with a front side of the ultrasound probe <b>106</b> and an opposite facing back side <b>353</b>B. The ultrasonic image of the blood vessel <b>351</b> can be depicted and stabilized on the display screen <b>104</b> of the ultrasound-imaging system <b>100</b> as shown in <figref idref="DRAWINGS">FIG. <b>3</b>B</figref>.

0066<figref idref="DRAWINGS">FIGS. <b>5</b>A-<b>5</b>B</figref> illustrate a subcutaneous target area of a patient for ultrasound imaging (i.e., for display in an ultrasound image) in accordance with some embodiments. Referring to <figref idref="DRAWINGS">FIG. <b>5</b>A</figref>, the predefined target area <b>502</b> for defining the ultrasound image includes a blood vessel <b>506</b> shown in conjunction with an image plane <b>353</b> (see <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>) defined by the ultrasound probe <b>106</b>. For illustration purposes, the predefined target area <b>502</b> may be synonymous with an ultrasound image that may be portrayed on the display <b>104</b>.

0067In some embodiments, the system <b>100</b> may determine or otherwise define a region <b>503</b> of the predefined target area <b>502</b> that encompasses the blood vessel <b>506</b>. In some instances, the identity of the blood vessel <b>506</b> as a vein vs. an artery may be unknown. According to some embodiments, the system <b>100</b> is configured to determine the identity of the blood vessel <b>506</b> as a vein or alternatively as an artery. In other embodiments, the system <b>100</b> may also be configured to determine the identity of one or more other anatomical elements within the ultrasound image, such as one or more nerves, for example. In some instances, the blood vessel <b>506</b> may be one of a plurality of the blood vessels (not shown) located within the predefined target area <b>502</b>. As such, the system <b>100</b> may be configured to determine the identity of more than one blood vessel within the ultrasound image.

0068The image plane <b>353</b> as defined by the ultrasound probe <b>106</b> may be oriented to be perpendicular to the blood vessel <b>506</b>. In other words, the clinician may adjust the position and/or orientation of the ultrasound probe <b>106</b> to establish an orientation of the image plane that is perpendicular to the blood vessel <b>506</b>.

0069In some embodiments, the identity of the blood vessel <b>506</b> may be at least partially determined by a proximity of the blood vessel <b>506</b> with respect to the ultrasound probe <b>106</b>. In other words, for some patients, the identity of the blood vessel <b>506</b> may be readily apparent due to a clinician awareness of the target area. For example, in some instances, the clinician may easily identify a basilic vein within a patient's arm. However, in other instances, the identification of the blood vessel <b>506</b> may be difficult to assess based on anatomical structure.

0070Typically, a blood pressure within an artery is greater than a blood pressure within a vein. Similarly, the structure of an artery may include a thicker wall than a vein. As such, a cross-sectional shape of an artery may often be rounder than a cross-section shape of a vein. More specifically, the cross-sectional shape of a vein may be more elliptical, or otherwise elongated, in contrast to the cross-sectional shape of an artery. In some embodiments, a length <b>510</b>A and a width <b>510</b>B of the blood vessel <b>506</b> may be obtained from ultrasound image data and processed according to the logic <b>120</b> to assess the shape of the blood vessel <b>506</b>. Accordingly, the identity of the blood vessel <b>506</b> may be determined based on the cross-sectional shape as further describe below.

0071With reference to <figref idref="DRAWINGS">FIG. <b>5</b>B</figref>, the identity of the blood vessel <b>506</b> may be determined based on a direction of blood flow within the blood vessel <b>506</b>. As the direction of the blood flow is in opposite directions in veins vs. arteries, an assessment of the blood flow direction may assist in identifying the blood vessel <b>506</b>. As the ultrasound probe <b>106</b> is configured to perform doppler ultrasound, the ultrasound probe <b>106</b> may obtain doppler ultrasound data. Therefrom, the logic <b>120</b> may determine a direction of the blood flow within the blood vessel <b>506</b> with respect to the image plane <b>353</b> (i.e., an orientation of the ultrasound probe <b>106</b>). In other words, in an instance where the clinician has oriented ultrasound probe <b>106</b> on the patient's arm so that a front side <b>501</b> of the ultrasound probe faces the patient's hand, a blood flow direction <b>507</b> (illustrated as going into the page) within the blood vessel <b>506</b> extending from the front side <b>501</b> of the ultrasound probe <b>106</b> toward the back side of the ultrasound probe <b>106</b> may be consistent with blood flow through a vein. Alternatively, a blood flow direction <b>507</b> within the blood vessel <b>506</b> extending from the back side of the ultrasound probe <b>106</b> toward the front side <b>501</b> (i.e., an opposite direction from the blood flow direction <b>507</b>) may be consistent with blood flow through an artery. As such, the logic <b>120</b>, upon determining direction of blood flow within blood vessel <b>506</b>, may identify the blood vessel <b>506</b> as a vein or alternatively an artery based on doppler ultrasound data.

0072In some instances, the anatomy of the patient and/or a vasculature operation of the patient may introduce some error in the determination of the blood flow direction within the blood vessel <b>506</b>. Such an instance may include a partially occluded or totally occluded blood vessel <b>506</b>. In some embodiments, the logic <b>120</b> may determine a confidence for the identification of the blood vessel <b>506</b> based on the direction of blood flow as further described below.

0073In some embodiments, the identification of the blood vessel may be determined via a magnitude (e.g., a velocity or flow rate) of blood flow within the blood vessel <b>506</b>. In some instances, a medical procedure may include identifying one blood vessel in relation to an adjacent blood vessel. For example, in some instances, a blood flow rate through an artery may generally be greater than a blood flow through an adjacent vein. As such, the identification of the blood vessel <b>506</b> may be determined in accordance with a magnitude of blood flow with the blood vessel <b>506</b> as further described below. In some embodiments, the logic <b>120</b> may also determine a confidence for the identification of the blood vessel <b>506</b> based on the magnitude of blood flow as further described below.

0074In some embodiments, the cross-section shape of the blood vessel <b>506</b>, such as the cross-section shape <b>508</b> of <figref idref="DRAWINGS">FIG. <b>5</b>A</figref> may be determined via ultrasound image data. In further embodiments, a blood flow related cross-section shape <b>509</b> of the blood vessel <b>506</b> may be determined via doppler ultrasound data as shown in the <figref idref="DRAWINGS">FIG. <b>5</b>B</figref>. In some instances, the cross-section shape <b>509</b> may be more elongated than the cross-section shape <b>508</b>, which may enhance (e.g., increase the accuracy of) the determination of the identity of the blood vessel <b>506</b> based on the cross-section shape. In some embodiments, the logic <b>120</b> may also determine a confidence for the identification of the blood vessel <b>506</b> based on the shape of the blood vessel.

0075In some embodiments, the identification of the blood vessel <b>506</b> may include an assessment of a pulsatility of the blood flow. Typically, arterial blood flow is more pulsatile in accordance with the heartbeat than venous blood flow. As such, the pulsatility of the blood flow within the blood vessel <b>506</b> may be used to identify the blood vessel <b>506</b>. According to one embodiment, the ultrasound probe <b>106</b> may obtain pulsatility data (i.e., doppler ultrasound data pertaining to the pulsatility of the blood flow) and provide the pulsatility data to the console <b>102</b> for processing. The logic <b>120</b> may then determine the identity of the blood vessel <b>506</b> based on the pulsatility data as further described below. In some embodiments, the logic <b>120</b> may also determine a confidence for the identification of the blood vessel <b>506</b> based on the pulsatility of the blood flow.

0076In some instances, the blood flow within the blood vessel <b>506</b> may be uneven (i.e., pulsatile) due to factors other than the heartbeat. In such instances, it may be advantageous to isolate the pulsatility related to the heartbeat from uneven flow caused by other factors. So doing may enhance an accuracy of a pulsatility assessment/measurement. As stated above, the system <b>100</b> may include an ECG monitor <b>170</b> for providing an ECG signal to the console <b>102</b>. The logic <b>120</b> may in some embodiments, utilize the ECG signal to isolate the pulsatility of the heartbeat from the uneven flow caused by other factors as further described below. In other words, the assessment of the pulsatility of the blood flow may be performed in coordination with the ECG signal.

0077The doppler ultrasound data may be obtained within a defined doppler ultrasound window <b>504</b> defining a portion of the ultrasound image. In other words, the logic <b>120</b> may define a portion of the ultrasound image within which motion/movement of elements may be assessed via doppler ultrasound. The doppler ultrasound window <b>504</b> encompasses at least the blood vessel <b>506</b> but may also encompass more than one blood vessel and/or other anatomical elements, such as nerves, for example.

0078In some embodiments, the doppler ultrasound window <b>504</b> may be automatically defined in accordance with detecting the blood vessel <b>506</b> within the predefined target area <b>502</b>, i.e., the doppler ultrasound window <b>504</b> may be automatically defined upon detecting the one or more blood vessels.

0079In some embodiments, the clinician may define the doppler ultrasound window <b>504</b> via input to the system <b>100</b> through an input device such as a computer mouse or other pointing device. In some embodiments, the input may be facilitated via a GUI interface of the display <b>104</b>. In other embodiments, the input may be facilitated via the control buttons <b>110</b> (see <figref idref="DRAWINGS">FIG. <b>1</b></figref>) on the ultrasound probe <b>106</b>. In some embodiments, the clinician may select the blood vessel <b>506</b> as a target blood vessel (or a blood vessel on interest) from among other blood vessel that may be included in the ultrasound image.

0080<figref idref="DRAWINGS">FIGS. <b>6</b>A-<b>6</b>B</figref> illustrate a subcutaneous target area of a patient for ultrasound imaging (i.e., for display in an ultrasound image) in accordance with further embodiments of the system <b>100</b>. Similar to <figref idref="DRAWINGS">FIGS. <b>5</b>A-<b>5</b>B</figref>, <figref idref="DRAWINGS">FIGS. <b>6</b>A-<b>6</b>B</figref> illustrate a blood vessel <b>606</b> within a predefined target area <b>602</b> (i.e., ultrasound image). Further illustrated within the predefined target area <b>602</b> in an additional anatomical element <b>611</b> shown as a bundle of nerves. However, the anatomical element <b>611</b> is not limited to a bundle of nerves. As such, the anatomical element <b>611</b> may comprise a bone, a ligament, a tendon, or another blood vessel. In similar fashion, more than one additional anatomical element <b>611</b> may be included in the predefined target area <b>602</b>. As shown in <figref idref="DRAWINGS">FIGS. <b>6</b>A-<b>6</b>B</figref> notifications may be superimposed atop the ultrasound image when the ultrasound image is portrayed on the display <b>104</b>. In some embodiments, the notifications include an identity <b>612</b> of the blood vessel <b>606</b> (e.g., “V” indicating a vein). The notifications further include indications of confidence as further described below. <figref idref="DRAWINGS">FIG. <b>6</b>A</figref> illustrates a scenario where the identity of the blood vessel <b>606</b> is determined without utilizing doppler ultrasound. Conversely, <figref idref="DRAWINGS">FIG. <b>6</b>B</figref> illustrates a scenario, where determining the identity of the blood vessel <b>606</b> includes doppler ultrasound.

0081In the exemplary instance shown in <figref idref="DRAWINGS">FIG. <b>6</b>A</figref>, the system <b>100</b> has determined that the blood vessel <b>606</b> is a vein at a confidence level <b>613</b> of 90%. Similarly, the system <b>100</b> as determined a confidence level <b>614</b> of 50% associated with the anatomical element <b>611</b>. In other words, as a result of the identity determination, the clinician may understand that the probability that the blood vessel <b>606</b> is a vein is 90%. Similarly, the clinician may understand that the probability that the anatomical element <b>611</b> is a vein is 50%. In other words, the probability that the anatomical element <b>611</b> is a vein is the same as the probability that the anatomical element <b>611</b> is not a vein.

0082Conversely, in the exemplary instance shown in <figref idref="DRAWINGS">FIG. <b>6</b>B</figref>, the system <b>100</b> has determined that the blood vessel <b>606</b> is a vein at a confidence level <b>623</b> of 95% with doppler ultrasound vs. the confidence level <b>613</b> of 90% without doppler ultrasound. Similarly, the system <b>100</b> as determined a confidence level <b>624</b> of 0% associated with the anatomical element <b>611</b> with doppler ultrasound vs. the confidence level <b>614</b> of 50% without doppler ultrasound. By way of summary, the utilization of doppler ultrasound when determining the identity of the blood vessel <b>606</b> and/or the anatomical element <b>611</b> enhances the confidence of the identity determination. As such, when doppler ultrasound is utilized when determining the identity of the blood vessel <b>606</b>, the clinician may more reliably avoid a blood vessel identification error when performing an intravascular procedure.

0083<figref idref="DRAWINGS">FIG. <b>7</b></figref> illustrates the console <b>102</b> portraying an ultrasound image <b>701</b> of the predefined target area on the display screen <b>104</b>. Depicted in the ultrasound image <b>701</b> is the blood vessel <b>606</b> (or more specifically an image of the blood vessel <b>606</b>). Superimposed atop the ultrasound image <b>701</b> are the blood vessel identity <b>612</b> and the confidence for the identity <b>623</b>. In some embodiments, a direction indicator <b>715</b> of the blood flow direction within the blood vessel <b>606</b> may also be superimposed.

0084In some embodiments, an iconographic representation <b>712</b> of the medical device <b>112</b> (<figref idref="DRAWINGS">FIG. <b>3</b>A</figref>) may also be superimposed atop the atop the ultrasound image <b>701</b> to assist the clinician in inserting the medical device <b>112</b> into the blood vessel <b>606</b>. In some embodiments, the iconographic representation <b>712</b> of the medical device <b>112</b> may serve as a pointing device similar to a computer mouse. For example, the clinician may adjust a position and/or orientation of the medical device <b>112</b> in relation to the blood vessel <b>351</b> (see <figref idref="DRAWINGS">FIG. <b>3</b>A</figref>) and thereby adjust the position of the iconographic representation <b>712</b> with respect to the image of the blood vessel <b>606</b>. In some embodiments, the clinician may provide input to the logic <b>120</b> via the iconographic representation <b>712</b> to define the doppler ultrasound window <b>504</b> (see <figref idref="DRAWINGS">FIG. <b>5</b>B</figref>). In some embodiments, the clinical may also select the blood vessel <b>606</b> as the blood vessel of interest among other blood vessels (not shown) that may be included in the ultrasound image <b>701</b>.

0000Methods

0085Methods of the foregoing ultrasound-imaging systems include methods implemented in the ultrasound-imaging systems. For example, a method of the ultrasound-imaging system <b>100</b> includes a non-transitory CRM (e.g., EEPROM) having the logic <b>120</b> stored thereon that causes the ultrasound-imaging system <b>100</b> to perform a set of operations for ultrasound imaging when the logic <b>120</b> is executed by the processor <b>116</b> of the console <b>102</b>. Any methods disclosed herein comprise one or more steps, actions or operations for performing the described method. The method includes operations (e.g., steps or actions) that may be interchanged with one another. In other words, unless a specific order of the operations is required for proper operation of the embodiment, the order and/or use of specific operations may be modified.

0086<figref idref="DRAWINGS">FIG. <b>8</b></figref> is a flow chart illustrating an exemplary method of the system <b>100</b>. The method <b>800</b> includes operations in accordance with a reference numbers <b>810</b>-<b>860</b>. Defining the ultrasound image (block <b>810</b>) may include activating include activating the ultrasonic transducers of the array of the ultrasonic transducers <b>148</b> of the ultrasound probe <b>106</b> communicatively coupled to the console <b>102</b>. With the activating operation, the ultrasonic transducers <b>148</b> emit generated ultrasound signals into the patient P, receive reflected ultrasound signals from the patient P, and convert the reflected ultrasound signals into corresponding electrical signals for processing into ultrasound images. The activating operations can include activating an approximately linear subset of the ultrasonic transducers <b>148</b> of a 2-D array of the ultrasonic transducers <b>148</b>. Alternatively, the activating operations can include activating a subset of the ultrasonic transducers <b>148</b> up to all the ultrasonic transducers <b>148</b> in the movable linear array of the ultrasonic transducers <b>148</b>.

0087The logic <b>120</b> may detect a blood vessel with the ultrasound image (block <b>820</b>). More specifically, the ultrasound probe may identify color or contrast changes within an ultrasound image that indicate a difference in subcutaneous tissue structure. In some instances, a blood vessel may appear as a black hole in an ultrasound image as defined by ultrasound image data. The ultrasound probe may provide the ultrasound data to the console where the logic <b>120</b> may define the black hole as a blood vessel.

0088The method includes doppler ultrasound operations applied to all or a portion of the ultrasound image. The doppler ultrasound operations including defining a doppler ultrasound window (block <b>830</b>). The doppler ultrasound window defines a portion of the ultrasound window for assessing motion of elements imaged within the doppler ultrasound window including blood flow within the blood vessel. In some embodiments, the logic <b>120</b> may automatically define the doppler ultrasound window to encompass one or more blood vessels upon detection of the one or more blood vessels within the ultrasound image.

0089In some embodiments, the logic <b>120</b> may automatically define the doppler ultrasound window <b>504</b> based on the comparison of the ultrasound image with the corresponding ultrasound images stored in memory <b>118</b>. For example, the corresponding ultrasound images in memory may include a predefined doppler ultrasound window. As such, the logic <b>120</b> may define the doppler ultrasound window <b>504</b> based on the predefined doppler ultrasound window of the corresponding ultrasound images in memory.

0090According to further embodiments, the logic <b>120</b> may receive an input as may be entered by a clinician via an input device, and the logic <b>120</b> may define the doppler ultrasound window based on the input. In other words, the clinician may select a portion of the ultrasound image as the doppler ultrasound window and the logic <b>120</b> may define the doppler ultrasound window in accordance with the selection. In some embodiments, the clinician may select a portion of the ultrasound image via the GUI such as with a computer mouse or touch screen. In other embodiments, the clinician may select a portion of the ultrasound image via the control buttons of the ultrasound probe.

0091In still other embodiments, the clinician may select a portion of the ultrasound image via the medical device. More specifically, the medical device tracking operations may track the medical device with respect to the predefined target area and depict the iconographic representation of the medical device atop the ultrasound image in real time so that the clinician may select the portion of the ultrasound image based on positioning of the medical device.

0092After detecting a blood vessel, the logic <b>120</b> may determine an identity of the blood vessel (block <b>840</b>). The determination of the identity of the blood vessel may include all or a subset of the logic operations described below. The logic <b>120</b> may determine a blood flow condition within the blood vessel by obtaining doppler ultrasound data. The blood flow condition may include a presence or absence of blood flow. The logic <b>120</b> may detect, via doppler ultrasound, a blood flow within the blood vessel and thereby further identify the detected black hole to be a blood vessel. The logic <b>120</b> may further determine a direction of the blood flow within the blood vessel with respect to the image plane (or more specifically with respect to an orientation of the image plane) and thereby, determine the blood vessel to be a vein or alternatively an artery. The logic <b>120</b> may also detect a non-flow condition of the blood vessel (i.e., absence of blood flow), and thereby, determine the blood vessel to be an anatomical element other than a blood vessel, such as a nerve or a bundle of nerves for example.

0093The operations may include identifying the blood vessel as a vein or an artery based on a blood flow rate or velocity within the blood vessel. The operations may include determining a flow rate (i.e., magnitude of blood flow) with the blood vessel and thereby identify the blood vessel as vein or an artery. For example, in some instances, the blood flow within a defined artery may generally be greater than a blood within an adjacent vein. Accordingly, the logic <b>120</b> may obtain a blood flow rate or velocity within a first blood vessel and further obtain a blood flow rate or velocity within a second blood vessel adjacent the first blood vessel. The logic <b>120</b> may then compare the determined blood flow rates and identify the blood vessel with the greater flow rate as an artery.

0094The operations may include identifying the blood vessel as a vein or an artery based on a pulsatility of the blood flow within the blood vessel. The logic <b>120</b> may measure, via doppler ultrasound, a pulsatility of the blood flow within the blood vessel. As the arterial blood flow is generally more pulsatile than venous blood flow, the logic <b>120</b> may compare a measured pulsatility with a predefined pulsatility limit stored in memory. The logic <b>120</b> may thereby determine the blood vessel to be (1) an artery if the measured pulsatility exceeds the pulsatility limit or (2) a vein if the measured pulsatility is less than the pulsatility limit.

0095In some embodiments, the logic <b>120</b> obtain an ECG signal, and determine the pulsatility of the blood flow in coordination with the ECG signal. By so doing, logic <b>120</b> may filter out pulse noise within the blood vessel as may be caused by patient movement, patient contact, or other external sources, thereby enhancing an accuracy or reliability of the pulsatility measurement.

0096In some embodiments, the logic <b>120</b> may assess the timing blood flow pulses within blood vessels. More specifically, the logic <b>120</b> may determine a timing difference between a blood flow pulse within a first blood vessel and a corresponding blood flow pulse within a second blood vessel based on doppler ultrasound data. Based on the timing difference, the logic <b>120</b> may identify one or both of the first blood vessel or the second blood vessel as a vein or as an artery. By way of one example, a blood flow pulse as defined a heartbeat travels along an artery toward an extremity of the patient, such as a hand for example, passing through the predefined target area at a first point in time. The same pulse travels in the opposite direction (i.e., toward the heart) along a corresponding vein, passing back through the predefined target area at a second point in time. The logic <b>120</b> determines that the second point in time follows the first point in time by the pulse timing difference. The logic <b>120</b> may then determine that the blood flow pulse passing through the predefined target area at the first point in time emanates from an artery, and the blood flow pulse passing through the predefined target area at the second point in time emanates from a vein. In such a way, the logic <b>120</b> may identify a blood vessel as an artery or as a vein. In some embodiments, the logic <b>120</b> may obtain pulse timing data in coordination with the ECG signal.

0097In some embodiments, the operations may further include identifying the blood vessel as a vein or an artery based on a spatial positioning of the blood vessel within the ultrasound image. In some embodiments, the logic <b>120</b> may compare the ultrasound image with one or more corresponding ultrasound images stored in memory. The logic <b>120</b> may more specifically compare the spatial positioning of the blood vessel within the ultrasound image with the spatial positioning of the corresponding blood vessel in the one or more corresponding ultrasound images, where in some embodiments, the spatial positioning includes a subcutaneous depth of the blood vessel. As a result of the comparison, the logic <b>120</b> may identify the blood vessel as a vein or alternatively as an artery.

0098In some embodiments, the operations may further include identifying the blood vessel as a vein or an artery based on a cross-sectional shape of the blood vessel. Typically, a blood pressure within an artery is greater than a blood pressure within a vein. Similarly, the structure of an artery may include a thicker wall than a vein. As such, a cross-sectional shape of the artery may often be rounder than a cross-section shape of a vein. More specifically, the cross-section shape of a vein may be more elliptical, or otherwise elongated, in contrast to the cross-section shape of an artery. In some embodiments, the logic <b>120</b> may determine a length and a width of the blood vessel from ultrasound image data. In some, the logic <b>120</b> may then determine an aspect ratio of the shape and compare the aspect ratio with an aspect ratio limit stored in memory. As a result of the comparison, the logic <b>120</b> may identify the blood vessel as (1) a vein when the aspect ratio exceeds the limit or (2) an artery when the aspect ratio is less than the limit.

0099The operations may include determining a confidence for the identification of the blood vessel (block <b>850</b>). The logic <b>120</b> may determine the confidence based on all or a subset of the identification operations described above. For example, the logic <b>120</b> may determine an individual confidence for each of the identification operations described above and determine a composite confidence for the identification. The confidence determination operation may take several forms. For example, the confidence regarding the identification based on the shape may include assessing a magnitude of difference between the determined aspect ratio and the aspect ratio limit stored in memory. By way of another example, the confidence for the identification based on the blood flow direction within the blood vessel may be greater when the blood flow rate is relatively high vs. relatively low.

0100The displaying operations further include portraying the ultrasound image on the display screen coupled with the console (block <b>860</b>). The displaying operations may further include superimposing a visual notification atop the ultrasound image. The notification may indicate the identification of the blood vessel. The notification may also include the confidence where the confidence includes a number (e.g., a percent probability) or other confidence indication such as a low, medium, or high-level indication of confidence.

0101Other methods may include magnetic signal-related operations. The magnetic signal-related operations can include a converting operation. The converting operation includes converting magnetic signals from a magnetized medical device (e.g., the needle <b>112</b>) with the magnetic-sensor array <b>146</b> of the ultrasound probe <b>106</b> into corresponding electrical signals. The processing operations further include processing the corresponding electrical signals of the magnetic signals with the processor <b>116</b> into distance and orientation information with respect to the predefined target area so that the iconographic representation of the medical device may be portrayed on the display screen <b>104</b>.

0102Other methods may further include a number of optical signal-related operations in combination with further processing and displaying operations. The optical signal-related operations include emitting input optical signals, receiving reflected optical signals, and converting the reflected optical signals into corresponding electrical signals of the optical signals by the optical interrogator <b>154</b>. The optical signal-related operations also include conveying the input optical signals from the optical interrogator <b>154</b> to the number of FBG sensors along the length of the optical-fiber stylet <b>156</b>, as well as conveying the reflected optical signals from the number of FBG sensors back to the optical interrogator <b>154</b> with the optical-fiber stylet <b>156</b> disposed in a lumen of the medical device. The processing operation further include processing the corresponding electrical signals of the optical signals with the processor <b>116</b> into distance and orientation information with respect to the predefined target area to assist in superimposing the iconographic representation of a medical device on the display screen <b>104</b>.

0103Other method operations can include a data-providing operation that includes providing positional-tracking data to the console <b>102</b> from the accelerometer <b>160</b>, the gyroscope <b>162</b>, the magnetometer <b>164</b>, or a combination thereof of the ultrasound probe <b>106</b> where the tracking data pertains to the position and/or orientation of the ultrasound probe with respect to a trajectory of the one or more blood vessels. Such, operations may enhance an accuracy of the determining of the direction and/or magnitude of blood flow within the one or more blood vessels.

0104While some particular embodiments have been disclosed herein, and while the particular embodiments have been disclosed in some detail, it is not the intention for the particular embodiments to limit the scope of the concepts provided herein. Additional adaptations and/or modifications can appear to those of ordinary skill in the art, and, in broader aspects, these adaptations and/or modifications are encompassed as well. Accordingly, departures may be made from the particular embodiments disclosed herein without departing from the scope of the concepts provided herein.